I have on occasion had a 1/4" router bit slip in the collet - and in fact that was the very reason that prompted my purchase of a PC 690 router kit. There was no PC 890 router yet, so that tells you how long ago that was. Anyways I try to use 1/2" shank bits as much as I can, although clearly that is not always possible.
Earlier this year I made an "exact-width" dado jig; there are many ideas out there, but I used The Wood Whisperer in general (several things I did not like about that). I hate dealing with offsets, and so decided to use a top bearing flush trim bit (top-bearing meaning the bearing closer to the router body than the cutter is). Since the primary purpose is to cut dadoes for 'undersized' plywood, I need to use a bit smaller diameter than 3/4" - so 1/2" cutting diameter it is. Those (I thought) are only available in 1/4" shank - so that's what I have used. 1/2" diameter, 1/2" cutter height, 1/4" shank - to pbearing. Bought at Klingspor's - their brand made by Whiteside I believe.
Cutting '3/4" ' dadoes in plywood for cabinets - this has worked great. A few items on the learning curve, but no real surprises.
Then this week I have tried using the jig and the same flush trip (or pattern bit, or template routing bit - lots of different names for this); the material this time was solid maple. I was cutting (hand held) about a 2" wide x 1/2" deep slot, 36" long. In attempting to do this I had the following sequence occur:
- the bit slip in the collet, (switched to another collet)
- the bit slip again, and the set screw fly out of the 'bearing holder ring thingy' (well I presume it did b/c it is no longer there; replaced it); switched to another PC 690 router
- the bit come out of the collet!!!!! No damage to me or really to project - (bit is toast, and collet was trashed)
So far two collets and two router have had this issue. So I
- bought a NEW bit and new collet
- had a repeat of all the above! New bit (tightened with HULK grip) came out of new collet in use within 3-4 minutes, and set screw was gone again!
Eventually I used a collar and a straight 1/2" bit on a 1/2" collet to hog out the waste (should have come to that strategy earlier!). Using this I was able to cut to depth, I just needed to flush up the sides of the groove. For that I now am the the not so proud owner of a new 3/4" cutter height top-bearing bit to 'flush up' the edges. THis bit worked for my needs today, but won't work for undersized plywood dadoes.
As I write this I think now that I was being too aggressive with the depth of cut; 3-4 passes for 1/2" deep cut. At the time I thought this was reasonable - 1/8" deep or so x 1/2" max (cutter diameter).
These are stopped cuts, so a Table saw dado set would not have been a good option - perhaps I should/could have wasted out a bunch with a track saw ?!?!?
Anyways - that's explains so of my disdain for 1/4" bits.
(NOTE - i have a 1/4" shank, solid carbide bit that I have used often to cut mortises many times) on the same router with the same collet.
Thanks for letting me vent!
Earlier this year I made an "exact-width" dado jig; there are many ideas out there, but I used The Wood Whisperer in general (several things I did not like about that). I hate dealing with offsets, and so decided to use a top bearing flush trim bit (top-bearing meaning the bearing closer to the router body than the cutter is). Since the primary purpose is to cut dadoes for 'undersized' plywood, I need to use a bit smaller diameter than 3/4" - so 1/2" cutting diameter it is. Those (I thought) are only available in 1/4" shank - so that's what I have used. 1/2" diameter, 1/2" cutter height, 1/4" shank - to pbearing. Bought at Klingspor's - their brand made by Whiteside I believe.
Cutting '3/4" ' dadoes in plywood for cabinets - this has worked great. A few items on the learning curve, but no real surprises.
Then this week I have tried using the jig and the same flush trip (or pattern bit, or template routing bit - lots of different names for this); the material this time was solid maple. I was cutting (hand held) about a 2" wide x 1/2" deep slot, 36" long. In attempting to do this I had the following sequence occur:
- the bit slip in the collet, (switched to another collet)
- the bit slip again, and the set screw fly out of the 'bearing holder ring thingy' (well I presume it did b/c it is no longer there; replaced it); switched to another PC 690 router
- the bit come out of the collet!!!!! No damage to me or really to project - (bit is toast, and collet was trashed)
So far two collets and two router have had this issue. So I
- bought a NEW bit and new collet
- had a repeat of all the above! New bit (tightened with HULK grip) came out of new collet in use within 3-4 minutes, and set screw was gone again!
Eventually I used a collar and a straight 1/2" bit on a 1/2" collet to hog out the waste (should have come to that strategy earlier!). Using this I was able to cut to depth, I just needed to flush up the sides of the groove. For that I now am the the not so proud owner of a new 3/4" cutter height top-bearing bit to 'flush up' the edges. THis bit worked for my needs today, but won't work for undersized plywood dadoes.
As I write this I think now that I was being too aggressive with the depth of cut; 3-4 passes for 1/2" deep cut. At the time I thought this was reasonable - 1/8" deep or so x 1/2" max (cutter diameter).
These are stopped cuts, so a Table saw dado set would not have been a good option - perhaps I should/could have wasted out a bunch with a track saw ?!?!?
Anyways - that's explains so of my disdain for 1/4" bits.
(NOTE - i have a 1/4" shank, solid carbide bit that I have used often to cut mortises many times) on the same router with the same collet.
Thanks for letting me vent!